The invention concerns a dosing arrangement for coating running webs with a blade in coating machines and the like. The dosing system employs a so-called doctor blade, wherein directly or at some distance, of perhaps 30-50 cm, a feed system for the coating mixture may be coordinated with the doctor blade along the periphery of a roll carrying the web of paper or cardboard. The arrangement also may be such that the paper web runs onto the roll only later, so that merely the roll shell receives a coating first, with the coating mixture being transferred only later from the roll shell to the paper web.
A categorical system is known from EP-A 04 26 980. This application describes, e.g., also a measuring system with a transmitter that emits light which is registered by a light-sensitive receiver arrangement, for instance in the form of a diode serial array or CCD camera. The output signal of this arrangement is then processed in order to adjust the angular position of the doctor blade in relation to the roll circumference, at the point of contact of the blade with said roll circumference. Despite their miniature style, all measuring systems described in this application still are relatively large and have a weight which is not quite negligible.
The problem underlying the present invention is to provide such a measuring device in which a sensor of noticeable weight is being avoided. Another problem, also, is to fashion the measuring system in such a way that a quick blade exchange, including the measured value transfer systems, is possible.